Ants are ectotherms or cold-blooded animals. This means that their internal physiological sources of heat are limited or even negligible and that they thus have to rely on external environmental sources such as sunlight for thermoregulation.
In this article we’ll look deeper into what being cold-blooded means for ants as we discuss their relationship with temperature. Specifically, we’ll look into why they need to thermoregulate and how either an increase or decrease in environmental temperature affects them.
Why Do Ants Need To Thermoregulate?
Temperature directly affects the metabolism of cold-blooded animals like ants and thus it plays an important role in their ability to function. Maintaining ideal temperature, which is around 75 to 95 degrees Fahrenheit (23 to 35°C) depending on the species, will allow for the different cellular processes in their bodies to be carried out normally. In these conditions, they are able to move, forage, grow, and reproduce freely.
However, when temperature is either too high or too low, ants would cease their activities and sometimes even completely pause growth and development. In the worst case, they may even end up dead.
How Do Changes In Temperature Affect Ants?
Temperature changes which lead to temperatures outside optimal range may cause physiological changes in ants. For example, during the cold season, lower temperatures cause some ant species to enter diapause, a hibernation-like state characterized by a suspended period of development.
During this state, ants become sluggish or even immobile as their metabolism slows and they cease all activities including feeding and reproduction. It’s worth noting though that not all ants are capable of diapause, and some simply enter a cold coma wherein they typically suffer high mortality.
On the other hand, studies have shown that even a slight increase in body temperature can cause ants to be disoriented and constantly fall over. A few degrees more from such a point, and they’re rendered immobile. In some cases, extreme heat may also lead to denaturation which may lead to a disruption in cell activity and cell death. Worst case, ants may overheat and die.
Aside from physiological changes, changes in temperature may also lead to change in behavior. For instance, the harvester ants Pheidole militicida have been shown to adjust their foraging schedule depending on temperature as they become diurnal or nocturnal to avoid the cold or the summer heat.
How Do Ants Thermoregulate?
Given the importance of keeping their body temperatures within ideal range, ants have developed several strategies for thermoregulation. There is of course, sunning and seeking for warm shelter like how ants do so in preparation for winter. Before dormancy, ants optimize their nests for heating by burrowing into deeper ground or by taking refuge under rocks or tree barks which serve as heat sources.
Aside from that though, ants also employ complex nesting strategies. For instance, red wood ants keep their nests heated by building it with materials with good insulating properties. They then maintain thermal homeostasis in the nest through the metabolic heat produced by ant workers and the tunnels and passages in the nest which serve as ventilation.
Do Ants Hibernate?
Ants don’t technically hibernate. Instead they enter a similar state called diapause wherein the primary difference lies within the fact that diapause involves a pause in growth in development.
Can Ants Survive The Cold?
Yes, ants can survive the cold given that they’ve prepared adequately. As mentioned, ants need to prepare for the cold season by seeking warmer shelter such as deeper ground or by nesting underneath heat collectors. But aside from that, they also have to fatten up as preparation for dormancy wherein they’ll need to rely on stored energy.
If they are able to do both, then they have a good chance of surviving the winter season. That is, given that they’re capable of diapause.
Can Ants Freeze To Death?
While some ants are capable of overwintering, some species which aren’t capable of diapause aren’t so lucky. Pharaoh ants for example, have been shown to suffer high mortality during the cold season to the point that they’re colonies get wiped out.
The same could be said for some tropical species incapable of diapause which instead enters a cold coma wherein survival isn’t guaranteed.
Are Ants Attracted To Heat?
Barring the extremes, yes ants are most definitely attracted to heat. As cold-blooded animals, they rely on heat to function and survive. And as it generally goes, ants are attracted to whatever it is that keeps them alive.
As cold-blooded animals, ants are reliant on external sources of heat and are greatly affected by changes in temperature. As such, they have developed several thermoregulation strategies which allow them to attain optimal temperature and maintain normal metabolism.
These strategies include seeking out warm shelter, and complex nesting strategies involving ventilation and heat gradients that not only promotes growth and development but also keeps them safe from the dangers of extreme temperatures.